Recuperative soaking pit



p 1931- A. CULBERTSON 1,824,876

REGUPERATIVE SOAKING' PI '1 Filed Sept. 9, 1927 i Patented Septr29, 1931 UNITED STATES PATENT OFFICE,

ALBERT L. CULIBERTSON, OI MOUNT VERNON, OHIO, ASSIGNOR, BY MESNE ASSIGN-MEN'IS, TO THE CHAPMAN -STEIN COMPANY, OF MOUNT VERNON, OHIO, A CORPORA-TION OF OHIO RECUPERATIVE SOAKING rrr Application filed September '9,1927. Serial No, 218,381.

The invention relates to soaking pits of the type wherein the air forcombustion is preheated by passing it through a recuperator heated bythe wwaste gases exhausted from the pit, and aims to provide'a furnacehaving various advantageous features of construction for protecting therecuperator from the slag taking care of the slag passing out of thepit, avoiding overheating of the furnace walls, admitting air to the recuperator, aflording access to the pit and other parts of the furnace,cooling the cleaning pit by air circulation, etc.

Further objectsand advantages of the invention will be input obvious andin part specifically referred to in the description hereinaftercontained, which, taken in conjunction with the accompanying drawings,

discloses a preferred embodiment thereof, such embodiment, howeverf isto be considered merely as illustrative 0 its principles. In thedrawing,

The sin le figure is a vertical section through a urnace constructed inaccordance with the invention.

In the illustrated form of the invention I have shown asoaking pit 1having a removable cover 2 and a bottom 3, adapted to receive ingots 4in the usual manners The air and gas for combustion come in respec--tively through one or more air conduits 5 I and gas conduits 6, whichlatter mix the gas Lwith the air prior to their entry into the soakingpit, thecombustible mixture being admitted into the soaking pit at theupper --'part ofone of its side walls in such manner tor the wastegasespass laterally in azigthat the gases of combustion first passacross the pit over the tops of the ingots and then turn downwardly asindicated by the arrows in the drawing in a horse-shoe shaped path,

until they pass out of the pit through one or more exhaust passages 7located at the bottom of the same side wall.

The exhaust gases then pass through a suitable recuperator or, heatinterchanger 8 which will not be described in detail as it may be of thet e shown in theUnited States Patent to tein No. 1,404,721 dated January24, 1922,\ in which type of recupera- ,toa

zag-path through the recuperator from top to bottom and are finally ledinto a'collecting flue 9 controlled by a damper 10 and communicatingwith the stack flue 11.

The air for combustion passes up vertically through a recuperator of theabove type athering chamber 12 located at the top 0 the recuperator andcommunicating with the air conduits 5 above mentioned. In accordancewith one feature of the invention I support the soaking pit above thebottom of an excavation, such as furnaces of the 'above type are usuallyinstalled in, so as afi'orded, which is particularly desirable in casethe chamber is to be used by operatives for other purposes ashereinafter described. In accordance with another feature of theinvention, I provide between the soaking pit and the recuperator, a slagpocket so associated with the path of travel of the waste gases as toreceive solid or liquid materials which the waste gases carry out of thesoak- .ing pit and also to trap molten slag which may flow over orthrough the bridgewall between the soaking pit and the slag protector.As shown the exhaust passage 7 leads into a chamber 16 at one side ofthe recuperator 8 and the slag pocket 17 is disposed beneath thischamber between an outer wall 18 of the furnace and an inner wall 19which is interposedbetween the slag pocket and a passageway 20 whichconducts the waste gases from one level to another in the recuperator.The wall 18 is provided with a door 21 which may be merely of removablebrick work, whereby slag maybe removed from the pocket 17, into chamber13.

I also prefer to provide for the admission of air to the waste gasesbetween the soaking pit and the recuperator, which may be accomplishedfor example, by providing an opening 22in the wall 18 or doorway 21, the

opening being normally closed, but being adjustable from chamber 13 asby pulling out bricks, to permit cool air to flow into the waste gasesand prevent the adjacent walls of the furnace from becoming overheated.In the same way unduly high temperatures within the recuperator may beprevented so that metal recuperators may be used if desired- I prefer toconstruct the walls of the furnace which surround the chambers 16 and 17and the waste gas passage 7 of special non-shrinking refractories, forexample, of special carborundum composition, to prevent the wallsfroms'agging under high temperature conditions such as are sometimesencountered. r

In accordance with another feature of the invention, a chamber 23 isprovided beyond; the side wall 24 of the soaking pit opposite to theside wall in which'the admission and exhaust passages are located, and adoor 25 similar to member 21 above described, is provided in side wall24, whichmay be removed when desired to permit access to the bottom 3 ofthe soaking pit from chamber 2 23. This construction permits the bottomof the soaking pit to be made or repaired from chamber 23 instead offrom above the pit by opening cover 2, thus relieving the operativesfrom the excessive heat which is encountered in conditioning the bottomfrom above as heretofore. may be employed leading from the bottom of thesoaking pit to the chamber 23 for tapping ofi molten cinder from thesolid bottom, a further slag tap 27 leading from the bottom of the pitto chamber 13 may beemployed when the coke braize bottom is used.

Furnacesuof the above type are customarily installed in banks orbatteries, a series of units being disposed side by side parallel to theplane, of the section upon which the single figure of the drawing istaken; A

, similar series of units will usually be dis posed on the left handside of the chamber 23 as the latter appears in the drawing, and thusthechamber 23 may serve all the units disposed on opposite sides althoughwhile each unit will have its own chamber 13 therebeneath, which isaccessible from cham- While a specific embodimentof the inventionhasbeen disclosed, it is obvious that many changes may be made thereinwithout departing from its principles as set-forth in the appendedclaims.

I claim: s

1. In combination, a soaking pit, means for admitting air and fuelthereto, a heat interchanger through which the air and the waste gasesof combustion pass, a waste gas passageway leading from the soaking pitto the heat interchanger, and means for admitting air to the Waste gasesbetween the soak- A slag tap 26 g 'pit and heat interchanger to cool thesurrounding walls. 1

2. In combination, a soaking pit having passageways leading into oneside wall thereof for admitting air and fuel thereto, a heatinterchanger for preheating the air from the heat of the wastegases'located on the outer side of and'adjacent said side wall, saidheat interchanger being connected to said air passageway and there beingalso a waste gas passageway leading from said side wall to said heatinterchanger, a chamber beneath said soaking pit, a slag pocket forminga depression in the bottom of said waste gas passageway and interposedbetween the soaking it and heat interchanger, and means a& said slagpocket and chaniben.

ording. communication between passageways leading into one side wallthereof for admitting air and fuel thereto, a heat interchanger forpreheating the air from the heat of the waste gases located on the outerside of and adjacent said side wall, said heat interchanger beingconnected to said air passageway and there being also a waste gaspassageway leading from said side wall to said heat interchanger, achamber beneath said soaking pit, a slag pocket forming a depression inthe-bottom of said waste gas passageway and interposed between thesoaking pit and heat interchanger, means affording communication betweensaid slag pocket and chamber, and means for conducting air from saidchamber and beneath said slag pocket into said heat interchanger.

4. The combination set forth in claim 2 wherein means is provided forconducting air from said chamber to said heat interchanger.

In testimony that I claim the foregoing, I

have hereunto set my hand this 2nd day of

